Wallabies snacking in opium poppy fields are getting "high as a kite" and hopping around creating crop circles.
Tasmania is the world's largest producer of legally-grown opium for the pharmaceutical market.
Tasmania attorney-general Lara Giddings told a budget hearing yesterday that she recently read about the wallabies in a brief on the state's large poppy industry.
She said: "We have a problem with wallabies entering poppy fields, getting as high as a kite and going around in circles.
"Then they crash. We see crop circles in the poppy industry from wallabies that are high."
A manager for one of two Tasmanian companies licensed to take medicinal products from poppy straw said wildlife and livestock - including deer and sheep - that eat the poppies are known to "act weird".
Tasmanian Alkaloids field operations manager Rick Rockliff said: "There have been many stories about sheep that have eaten some of the poppies after harvesting and they all walk around in circles."
Tasmania supplies about 50% of the world's raw material for morphine and related opiates. About 500 farmers grow the crop on 49,420 acres of land.